• Please review our updated Terms and Rules here

DEC Rainbow HDD problem

Well, that may continue to point to the rainbow disk controller.

Paul, it's the RUX50 technical manual. I will scan it this weekend for you (then send a copy to Al at bitsavers. PM me with your proper e-mail address.) I wish it was the print set, but it's what we've got.... Mr. RSX11M+, do you have the RUX50 print set?

Lou
 
I actually might be getting another controller for the Rainbow. If I get it I will let you guys know what happens.

Does anybody happen to know where I could find the hard disk utility program disk for the Rainbow?
 
Lou - N2MIY said:
.... Mr. RSX11M+, do you have the RUX50 print set?
Click to expand...
I'll check next time I'm there - time permitting. Pretty sure I do not have a hardcopy. Fiche may be another story. I think we bought one of those options for our 11/84 at one point, but it's not a machine I was very much involved with unless something went awry so the recollection is not clear.

We once did a project to offer a variation of our "product" on a PRO-380 platform. A number of things came to light as we figured out how to compile RSX for it. (POS and MicroRSX were related family trees) While the hard drives themselves were the same as for other MFM options in the DEC line, I think controllers were always unique to the platform. I expect Rainbows to have been likewise.
 
Thanks for looking into the print set.

I just thought of another avenue of troubleshooting to take. I am going to run the memory diagnostics. I read in the installation manual for the drive that the option needs at least so much memory to work. I wonder if bad RAM could cause a problem.
 
The Rainbow would tell you about bad ram on startup. I know, because the Rainbow (100A+) I have had a bad bit in the ram that is soldered to the motherboard. I found the offending IC and replaced it. I am thinking your problem is your Rainbow disk controller. You can let us know when you try the replacement. Certainly hold on to the broken one for when the print set for it turns up.

Also, the RUX50 we're talking about here is a little off your main topic. It was a Unibus controller for the RX50 drive (it's not the Rainbow controller for the RD51).

As for the winchester disk utility program, I did find it on the internet somewhere, I think. I'll dig through my disks and update this post in a few minutes.....

Ok, I did not download it from the internet, I had an original DEC RX50 floppy. I just made an Imagedisk image of it. If you send me your proper e-mail address in a PM I will e-mail you the disk image. You will need a PC with a 5-1/4" 1.2MB floppy drive (RX33) and Dave Dunfield's Imagedisk: http://www.classiccmp.org/dunfield/img/index.htm

Lou
 
Last edited:
Thanks for the heads up with the memory check.

Okay. I didn't realize that it was different. That is no problem that it is slightly off topic.
 
I just received the controller today and I put it into the system, and I still get the same symptoms that the other controller produced still occur. 1 or 2 of the diagnostic subtests for the drive pass with the new controller that didn't pass with the old one.

Using the boot floppy, I tried runing the hdscan from another disk I have, and I also tried using diskpart on that disk. Hdscan, when I attempt to scan the hard drive says invalid drive specification. When I run diskpart it says that the drive is not formatted, and I need to format it. I am afraid to proceed because I want to try to salvage the disk first before trying something that drastic.

When I try to run the BYE program from the disk, the drive access light does not even light to indicate that it is moving to the parking zone.

I have not tired to run WUTIL and DEC's utility yet. I need to figure out imagedisk first.

Do you guys have any more troubleshooting suggestions?
 
Are you pretty sure that the disk controller from Ebay was good?

Do you have any friend that could loan you an RD51 (Seagate ST-412)? Do you have a friend who coupld put your RD51 in their working rainbow?

Lou
 
I am not certain that the controller is good because the seller said it was untested. But I have no reason to believe that it is bad.

Unfortunately I do not know anybody who could loan me a drive or let me use their rainbow to test the drive with.
 
Sorry to bring back an old thread, but I thought I would mention what I think the problem is.

The drive's seek mechanism appears to be bad. The noise that the drive makes is the stepper motor not being able to step. I lightly tapped the flag on the motor that is used for track 0 detect and it moved on its own. Is there any way I could fix this or is the drive pretty much bad now? I was thinking about moving it back and forth but I do not want to damage the surface of the drive.
 
That is a typical problem for RD51. You need to work the grease a bit to loosen things up.

Read this closely and decide if you want to take the risk. I do this, but I have had several RD51s open and have a feel for what I am doing.

Spin the drive up all the way. Quickly disconnect the power and move the head stepper by hand (I find the flag easiest to grab). Work it back and forth quickly for a couple seconds, returning the shaft to the position where the flag is back blocking the photointerrupter. The flag had better be tight on the shaft if you grab it. Disconnecting the power de-energizes the stepper so you can move it (it's very stiff otherwise.)

You have to be quick about this, because the point is to have the heads still flying over the disks and return them home before ever touching the data area.

Lou
 
Last edited:
Okay. I think I will go ahead and try it because I don't really have any other options, or is there another way to get it to work? Also is the landing zone of the disk when the flag is in the photogate or when it is far away from the photogate? Probably what my strategy will be so as not to damage the disk will be to move it back and forth once, and then repeat the process if necessary.
 
Well I have attempted the procedure several times, and I am unsuccessful. When I tried to run the Rainbow diagnostics disk the first 10 or so tests pass but when it goes to the scan/seek (something like that) it fails. The test before that tries to move the head throughout its range but it needs some help from me, it still passes even though I helped it along. The next test fails with error: HEAD POSITION. I think that this error is related to the stepper motor problem. I then skip that test and move on to the next tests which also fail. When it made it to the track 0 read test it says that there is a bad sector.

I still have some hope that it is related to the stepper motor problem though. What do you think? Although at this point I am afraid that track 0 might actually be bad.
 
Old Computers said:
I have some good news and some bad news. The bad news is that the boot floppy can't access the winchester drive and it says that the drive is uninitialized, and fdisk will not run terminating with the message that the partition information cannot be found. The good news is that the drive might not be crashed. The diagnostics disk indicates that the controller may be at fault. The drive passes its checks on cylinders, motor speed and similar things, but the other tests terminate with the message drive not ready or (I can't remember the exact wording) Winchester controller status: incomplete check. I believe that if the drive had crashed then it would give other errors, and that the drive would have attempted to seek, but I do not hear the drive attempting to seek when these tests are being run. The way the diagnostics behave suggests to me that the fault is with the computer and not the drive.

Drive A has also started to produce some read errors. I had to boot the diagnostics from drive B eventually because drive A would say system load incomplete or it would just freeze with the access light illuminated (although I could still access setup to reset the computer).
Click to expand...

Sorry to jump in so late.
Have you tried to format the disk via CP/M?
I had an uninitialized disk which was accessible via OS but couldn't boot because i accidentally deleted MBR and partition information. With either FDISK or Disk Management Tools (win7) i could not do a thing, but formatting first in CP/M and then in MS-DOS could help.
I don't know if it's gonna work, probably not, but you might give it a shot.
 
The test before that tries to move the head throughout its range but it needs some help from me
Click to expand...
As in you manually step it through, or give just enough force to let it step on its own? If the latter you might have something in the servo control giving a weak signal for the stepper, or the stepper itself has a shorted winding.
 
@Jack, I have not tried to format it in CP/M. I might try that if the drive still doesn't work even after figuring out the stepper motor's problem.

@NeXT, I have to push the flag to get it to move, but after pushing it moves on its own for a small distance then I have to do it again. Some places it will move on its own and other places I have to push. One thing that I have noticed though is that the motor still appears to want to step when it is in one of the places where it does not want to move. For instance when it tries to seek track zero it stops at a certain point and then makes a vibrating noise, and the flag moves back and forth very fast in that spot.
If it is shorted I assume that I am out of luck. If it is a weak signal how do I determine that?
 
Hi, Im not familiar with the drive but that is exactly what a stepper motor will do if its missing a phase, either a winding down or more likely a phase down in the actual driver, how many wire go into the stepper, can you get a scope on them ?
Dave
 
You must log in or register to reply here.
Back
Top